up in the middle of the night?
yeah pretty much :)
so what's happening?
I'm playing with a hardware step generator, but not sure I can get the bugs out
(for the pluto board)
what's sent to the pluto?
desired speed/dir for an axis?
the hal driver would take position, not velocity, as input
oh, so it's position/axis?
and over a certain time?
the communication between the HAL driver and the card is as you said at first: speed and direction
the HAL driver does the conversion from position command to velocity command
[00:33:03] <jepler> http://emergent.unpy.net/index.cgi-files/sandbox/pluto-step-following-error-2.png
[00:35:55] <jepler> http://emergent.unpy.net/index.cgi-files/sandbox/ferror-close-up.png
not bad :)
I wonder if this is due to a bug, or the quantization of the velocity request, or something else .. it sure has a distinctive pattern
hmm, now it's much too late here
wouldn't quantisation do that?
scale is 10000 steps per unit
= 1/5 div on that second screenshot .. so maybe
I mean, the jitter in the error, not the error itself
the error is proportional to the speed, and for constant inputs it seems to settle on the nearest count and not jitter
so maybe it's right
I just need a stepper to test it on :-P
anyway .. 'night
sigh, I can't find bit sizes that do everything I want: 4 axes worth of stepgens to fit on the pluto, a high maximum step rate, but minimum nonzero step rate less than 1 step per ms
saw the discussion about jogwheel direction
there was no rhyme or reason to it, just what happened
the scale values could be made negative to reverse one or more axes
oh it's perfectly sane considering the sign of the tool movement
I just don't like it because Y and Z feel backward compared to a manual machine
I'd probably set mine with some negatives, but it would probably surprise anyone else using it
jmkasunich: sure looks like there's another ppmc bug doesn't it
the latest email implies that its noise or crosstalk
a spike of noise exactly every .020 inches of movement?
seems unlikely to me
well, Jon grounded his shield and it magically went away for him
I thought at first that every 400 counts could be a 1 bit error - but wrong 400
you mean, 400 is not octal in this case?
or do you mean something else?
right, I was thinking 0x400 but that's wrong
so what does anyone think about merging nineaxis?
as in "before or after 2.2?"
I wonder if we've broken all the guis
tkemc has the very surprising behavior of showing X Y Z C A B
mini shows X Y Z A B C correctly
xemc shows X Y Z like it always does
so they need a little massaging, but they're not totally broken
I definitely like the new error checking for undefined axes. it's a big improvement.
yeah -- that would be nice in trunk whether nineaxis is merged or not
lathe seems to work
even when I take out the complete [AXIS_1] section
jmkasunich: I think the pluto step generator is working, though I haven't been able to really scope the step waveform yet
the waveform looks OK in simulation though
pluto-step works well enough to run emc .. but still no motors to turn with it
4 axis step plus dio?
15 din 13 dout 4 stepgen
no pwm, no watchdog, no encoder
that's a lot of IO
er, 16 din, 14 dout
yes it is plenty for stuff like limit switches
jepler: what do you need to test pluto-step? functional iron with motors or would just steppers/driver on a bench work?
Skullworks-PGAB: I'll probably bully chris into letting me try it on his mill, but one stepper motor and driver would be nice too
cradek still using a 297/298 half step driver?
I have a hobbyCNC 4 axis unipolar driver and 200 oz/in motors that I shelved - was planning a router table then came to my senses as I have no place to store the thing.
allows 1/2 to 1/16 step
I was just reading the page about that driver
if it would help for testing I could ship it - I have no plans for it.
sounds like a decent board
the fixed chopper makes noise - and its unipolar - but otherwise its a great entry unit.
aside from being unipolar
* jepler has a little debate with himself
how much are you looking for?
further the cause
at that price I hardly see how I could turn it down
except it probably means I have to deliver on pluto-stepper
when the code is ready - its ready... and I wouldn't be using it anyway...
besides - there are other applications you might be able to use it for.
will you send them USPS or some other service?
my friends and I joked about using it to make a penn ploter to mount on the wall over a white board to draw stuff during presentations...
yeah likely USPS
jepler: maybe you'll finally have something cnc
cradek: yeah I only have to build the rest of the machine in that case
Skullworks-PGAB: then send it to: Jeff Epler / 1666 Burr Street / Lincoln NE 68502
Skullworks-PGAB: you're sure you don't want any payment?
* cradek thinks jepler should pay shipping
nope - you guys work hard enough as is
wow it's like christmas
200 oz-in is real motors for a small machine
I have the address saved - I'll get everything boxed up and see if I can blackmail my cousin to get it to the Post Office
During the week I work 5a to 5p and its a 45 minute drive so I can never get in the door while there open.
they don't set their hours with the convenience of their customers in mind.
its a .gov job - hardcopy spam delivery
cradek: yeah I think the flaw in your reasoning is that we are not the post office's customers
Skullworks-PGAB: let me know when it does get mailed, so that I can start getting impatient for its arrival
hey - did either of you need anymore of those MAXON gearmotor servos like you used on your etch-a-sketch? - On impluse I bought like 10 and for the life of me I have no idea why. - I can throw some in the box also.
* Skullworks-PGAB might actual have a clean spot on his desk....
I should probably say "no"
on the other hand, there are moments I regret that I didn't buy like 10 extra because clearly they have some good use
I think I was reasoning that I could salvage the encoders
which I did one one
its quite a job - they used glue at one point - tamper proofing
yeah they do not just snap apart by any means
but its doable - its just a small count and 3mm shafe size - makes it a pain to reuse
they're just 100 lines or something, right?
100 line - no index
the disc was marked once I got it open
use a towel on the table so they don't bounce off the face of the earth and fall into the abyss
Error: Project requires 614 logic cells, but the selected device can contain only 576 logic cells
4 step + 1 PWM + 1 quadrature doesn't fit
seen you're starting to build a cnc
* alex_joni grins
something like that
I am pretty sure I'm what is derisively called a "motor spinner"
* alex_joni looks up "derisively"
* cradek looks around, with a bit of panic, for his notes about how this used to be wired
* jmkasunich is a motor spinner too
I did some CNC work today with emc2 :P
cradek: what's "this"?
mill spindle motor
cradek: I know it goes against your beliefs, but you really should document yoru machine ;-)
black green orange white red ...
eenie meenie minie moe
jepler: found a scsi card you can have if you still need one
cradek: OK, I'll let you know
argh, I got it together, and it's totally dead.
jepler: do you have any leftover new thinkpad nipples?
cradek: I suspect I would never find them
that's ok, thanks
they're cheap on ebay
no, I don't think it should cost three times as much to ship three nipples...
[23:53:21] <cradek> http://xkcd.com/c243.html
they need to be carefully packed - of course shipping more costs more!
man I hate motors with brushes you can't insert after assembling the motor
you need 12 hands and toothpicks to put it together
[23:58:47] <jmkasunich> http://xkcd.com/c231.html
and, usually, x-ray vision
yep, I like that one too
what a great comic